In the treatment of orthopedic disorders of the back and spine it has long been recognized that relief of pain and therapy results from the placing of the back and spine in traction or extension. Such extension treats injury due to compression of the spine vertabrae and disks, and individuals with chronic middle and lower back pain often find relief for extended periods of time by placing the middle and lower back in traction for a relatively short duration.
A wide variety of traction and extension devices exist, and it is known to use the weight of the patient for traction producing purposes, rather than employ artificial "dead" weight through weight, pulley and cord systems. Examples of traction devices utilizing the weight of the patient are shown in U.S. Pat. Nos. 3,353,532 and 3,716,049.
Specially designed traction apparatus is usually found in hospitals and physical therapy centers and are not readily available to patients in their homes and places of business. While relatively long term relief of pain can often be obtained by placing the back in traction for a relatively short period of time, the inconvenience of visiting a medical center for a traction treatment often prevents frequent visits and back pain is endured because of a lack of ready availability of convenient traction means. While "hang" bars may be mounted in doorways from which patients may suspend themselves by their arms, and "home" traction apparatus is known, most available devices either require excessive exertion on the part of the patient or are large and bulky and troublesome to set up and use.
It is known to incorporate therapeutic apparatus into chairs, examples being shown in U.S. Pat. Nos. 2,786,512 and 3,975,051. It is also known to incorporate traction structure for the head, back and spine into chair-type devices as shown in U.S. Pat. Nos. 913,127; 951,560 and 3,768,464. However, known chair devices are unsightly, complicated, expensive and obviously of such special purpose construction as not to readily blend with ordinary house or office furniture, or to be generally usable for nonorthopedic treatment purposes.
It is an object of the invention to provide a therapeutic traction chair for the treatment of back and spine problems wherein the chair is of attractive appearance, usable for general purpose applications, and is relatively economical to manufacture.
A further object of the invention is to provide a therapeutic traction chair capable of effectively producing a controlled degree of traction on the middle and lower back regions under comfortable conditions requiring minimal exertion on the part of the patient.
Yet another object of the invention is to provide a therapeutic traction chair having a seat and backrest wherein arm supports mounted on the backrest extend under the arms of the patient at the shoulders, and the seat is lowered relative to the backrest to transfer the patient's weight to the arm supports for traction purposes.
An additional object of the invention is to provide a therapeutic traction chair utilizing arm supports extending from a backrest wherein the arm supports may be pivoted between operative and inoperative positions, and may be vertically adjusted with respect to a seat permitting the chair to be adjusted for the most comfortable positions for a given patient.
A further object of the invention is to provide a therapeutic traction chair employing a subframe mounted upon a supporting frame in an adjustable manner wherein the subframe includes a seat and backrest, and an electric actuator movably adjusts the subframe relative to the support frame, and also functions to position the seat to the backrest to control the extent of traction imposed upon a patient supported by arm supports located under the arms and mounted upon the backrest.
The therapeutic traction chair in accord with the invention includes a support frame which rests upon the floor. A subframe is pivotally mounted upon the support frame and includes a seat and backrest, the pivot axis of the subframe being located at a region rearward of the seat front edge. The subframe includes a backrest support supporting a backrest cushion, and a seat support is pivotally mounted on the subframe adjacent the seat forward edge and includes a seat cushion.
At its upper regions the backrest support mounts a pair of spaced arm supports which extend from the backrest for selectively engaging the chair occupant below the arms at the shoulder extending under the armpits. The arm supports are, preferably, both vertically and horizontally adjustable, adjustment in the vertical direction being made through a head rest mounted upon the backrest support, and, preferably, the arm supports are pivotal between use and nonuse positions wherein the arm supports may be moved to a storage or nonuse position when the chair is being used for standard or nontherapeutic purposes.
An electric linear actuator is interposed between the support frame and the subframe. This actuator may be of the electric motor drive type utilizing a threaded or ball nut apparatus for linearly bi-directionally moving an element depending upon the direction of motor rotation. The actuator is pivotally mounted at one end upon the support frame, and at the other end is pivotally attached to the seat support adjacent its rear region, i.e. the region adjacent the backrest.
A stop located upon the subframe limits the pivotal movement between the subframe and seat structure. For instance, upward movement of the rear region of the seat structure will cause the seat structure to engage the subframe stop and the seat will be in a normal relationship to the backrest, and extension of the actuator pivots the subframe in an upward direction. The weight of the chair occupant is transferred from the subframe to the support frame by the subframe pivot and by the actuator.
In use, the chair occupant is seated on the seat with the rear region of the seat support engaging the backrest. For traction purposes, the arm supports will be extending under the armpits. Retraction of the linear actuator permits the entire subframe to pivot in a backward direction which transfers a greater portion of the occupant's weight to the backrest. At a preadjusted and predetermined pivotal position of the subframe, pivoting of the subframe relative to the support frame ceases and further retraction of the actuator lowers the rear portion of the seat relative to the backrest as the seat structure pivots about its pivot axis located on the subframe.
As the rear portion of the seat "drops away" from the backrest, the primary portion of the chair occupant's weight previously supported by the seat is now supported by the arm supports placing the back and spine under traction due to the occupant's weight. The extent of such traction is determined by the angle of the backrest to the vertical, and the degree of lowering that has occurred in the seat.
The chair occupant will remain in the traction condition as long as desirable, and the traction treatment is terminated by the chair occupant energizing the actuator toward an extended condition which "raises" the rear portion of the seat structure toward the backrest and upon the seat structure engaging the subframe stop further actuator extension pivots the subframe, including the seat and backrest, forward toward a normal upright position.
As the tilting of the backrest permits a predetermined portion of the chair occupant's weight to be transferred to the backrest, the degree and extent of extension of the back and spine can be accurately regulated to provide a comfortable, yet effective treatment. The padded arm supports comfortably engage the occupant's arms, and the attitude of the lowered and associated leg rests also contribute to the occupant's comfort. Accordingly, a therapeutic chair in accord with the inventive concepts is able to effectively relieve pain and discomfort existing in the middle and lower back with neglible inconvenience or discomfort to the user, and yet the apparatus is aesthetically acceptable in a home or office environment and capable of being used in a nontherapeutic manner.